diff options
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/debuginfo.rs | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs b/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs index f1eae605da0..ea59e183118 100644 --- a/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs +++ b/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs @@ -320,6 +320,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { ) -> Option<IndexVec<mir::Local, Vec<PerLocalVarDebugInfo<'tcx, Bx::DIVariable>>>> { let full_debug_info = self.cx.sess().opts.debuginfo == DebugInfo::Full; + let target_is_msvc = self.cx.sess().target.is_like_msvc; + if !full_debug_info && self.cx.sess().fewer_names() { return None; } @@ -341,11 +343,29 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { && var.source_info.scope == mir::OUTERMOST_SOURCE_SCOPE { let arg_index = place.local.index() - 1; - - // FIXME(eddyb) shouldn't `ArgumentVariable` indices be - // offset in closures to account for the hidden environment? - // Also, is this `+ 1` needed at all? - VariableKind::ArgumentVariable(arg_index + 1) + if target_is_msvc { + // Rust compiler decomposes every &str or slice argument into two components: + // a pointer to the memory address where the data is stored and a usize representing + // the length of the str (or slice). These components will later be used to reconstruct + // the original argument inside the body of the function that owns it (see the + // definition of debug_introduce_local for more details). + // + // Since the original argument is declared inside a function rather than being passed + // in as an argument, it must be marked as a LocalVariable for MSVC debuggers to visualize + // its data correctly. (See issue #81894 for an in-depth description of the problem). + match *var_ty.kind() { + ty::Ref(_, inner_type, _) => match *inner_type.kind() { + ty::Slice(_) | ty::Str => VariableKind::LocalVariable, + _ => VariableKind::ArgumentVariable(arg_index + 1), + }, + _ => VariableKind::ArgumentVariable(arg_index + 1), + } + } else { + // FIXME(eddyb) shouldn't `ArgumentVariable` indices be + // offset in closures to account for the hidden environment? + // Also, is this `+ 1` needed at all? + VariableKind::ArgumentVariable(arg_index + 1) + } } else { VariableKind::LocalVariable }; |